[Morphological and biochemical studies on glycogenosis type V (McArdle) (author's transl)]. / Zur Morphologie und Biochemie der Glykogenose Typ V (McArdle).

This report deals with structural and biochemical studies of muscle biopsies from six patients with glycogenosis type V (McArdle). From a morphological point of view in four cases the typical findings of vacuolar myopathy with glycogen storage especially under the sarcolemma can be demonstrated. One biopsy shows only mild structural changes which without additional biochemical analysis could be overlooked. In one case signs of recovery phase after rhabdomyolysis predominate the storage myopathy. Biochemical studies in all cases show an elevated glycogen content (2.5-4.23%). Only the from a clinical point of view most expressive patient with recurrent episodes of rhabdomyolysis exhibits a glycogen storage over 5%. All cases additionally show an absence or highly reduction of phosphorylase activity. Apart from the most expressive clinical course the extent of morphological and biochemical findings is not clearly correlated. Therefore if clinical signs suggest the diagnosis of glycogenosis type V it appears necessary to perform additional biochemical examination of muscle biopsy independent from the degree of morphological anomalies.

[Muscle biopsy in progressive external ophthalmoplegia (author's transl)]. / Wertigkeit der Skelettmuskelbiopsie bei progressiver externer Ophthalmoplegie.

In skeletal muscle biopsies of nine patients with progressive external ophthalmoplegia of unknown origin "ragged red" fibers can be demonstrated. The occurrence of these abnormal fibers does not correlate with clinical muscle weakness, or additional signs of the ophthalmoplegia plus syndrome. Rarely, "ragged red" fibers are seen in other neuromuscular disorders but usually these are associated with various structural alterations. Numerous "ragged red" fibers in an otherwise normal muscle provide an essential criterion in establishing the diagnosis of the ophthalmoplegia plus syndrome.

[Diagnostic value of muscle biopsy findings in myotonic dystrophy (Curschmann-Steinert) (author's transl)]. / Wertigkeit der Muskelbiopsie in der Diagnostik der Dystrophia myotonica (Curschmann-Steinert).

By histological, enzyme histochemical, histometrical and ultrastructural studies of 15 muscle biopsies from patients with myotonic dystrophy the typical morphological picture of a myopathy with multiple internal nuclei, sarcoplasmic masses and ring fibers can be shown only in 7 cases with very severe or prolonged clinical course. There is fiber degeneration under the sarcolemma which corresponds to findings in myopathies caused by hypothyroidism. Type-I-fiber-atrophy, which is thought to be an early morphological sign of the disease. can be demonstrated in our material only in proximal muscle groups, especially biceps muscle, whereas tibialis anterior muscle shows a slight focal atrophy of both mean fiber types, which is not helpful for differential diagnosis. Therefore in early cases of myotonic dystrophy which are not clarified by clinical and electromyographic investigation, a biopsy of biceps muscle should be done. Advanced cases as a rule can be confirmed by EMG without muscle biopsy. The morphological differential diagnosis of type-I-fiber-atrophy and the similarities of fiber degeneration under the sarcolemma in myotonic dystrophy as well as in myopathy caused by hypothyroidism are discussed.

[Congenital centronuclear myopathy. Two morphological variants in one family (author's transl)]. / Congenitale centronucleäre Myopathie. Zwei morphologische Varianten in einer Familie

This report deals with a family in which the mother and her two daughters suffer from a congenital, slowly progressive neuromuscular disease. Histological, histochemical and ultrastructural observations of the mother's muscle biopsy reveal the characteristics of the centronuclear myopathy. In this case central nuclei and pericentronuclear abnormalities of muscle fibers are found in almost all fibers. Biopsies obtained of the two daughters show alterations especially of type I-fibers, which often are smaller than normal. The presence of these two forms of centronuclear myopathy in one family indicates that these may be only different morphological types of states of one illness. Additionally, other structural findings (rod bodies, core like regions) emphasize the similarities with other congenital slowly progressive myopathies (nemaline myopathy, central core disease).

[Central core disease with "structured cores" in type II-fibers (author's transl)]. / Central core disease mit "structured cores" in Typ II-Fasern

Report on a sporadic case with congenital slowly progressive neuromuscular disease. Light microscopic, ultrastructural and histochemical changes of muscle biopsy reveal the characteristics of central core disease with "structured cores" in type II-fibers.

An especially mild myopathic form of glycogenosis type II. Problems of clinical and light microscopic diagnosis.

Report of a 20 months old child showing a mild form of glycogenosis type II (POMPE, 1932) with preferential involvement of skeletal muscle. First muscle biopsy reveals, on light microscopic examination, only a mild vacuolar myopathy. By PAS-staining pathologic glycogen storage can be shown. Glycogenosis type II is proved by ultrastructural and biochemical studies of muscle tissue obtained by a second biopsy. Consequently in all cases of a floppy infant syndrome with myopathic features it is necessary to obtain tissue for biochemical and ultrastructural analysis and to carry out these techniques if by light microscopic examination a vacuolar myopathy with increase of glycogen is found.